Quantitative steganalysis of least significant bit matching revisited for consecutive pixels

摘要

Least significant bit matching revisited (LSBMR) steganography uses two adjacent pixels as an embedding unit to conceal secret messages. In each unit, the modification probability of the first pixel is twice the modification probability of the second pixel, thereby causing an asymmetric effect on the statistical distribution of pixel difference in LSBMR for consecutive pixels (LSBMRCP). On the basis of the analysis of this asymmetric effect, a fast steganalytic feature is deduced and an embedding rate estimating method that employs an iteration strategy is proposed. Experimental results show that the steganalytic feature can effectively detect LSBMRCP steganography and that the detection performance is superior to the methods proposed by Tan and Xiong et al. Moreover, the embedding rate estimating method is so accurate that the order of magnitude of prediction error is maintained at 10~(-2), measured by the mean absolute error, median absolute difference, and interquartile range, thus indicating that the proposed method significantly outperforms the method proposed by Tan.